Fix race condition between setting developer mode and config fetch (#5600)

Author: paulb777

FirebaseRemoteConfig/CHANGELOG.md

@@ -1,3 +1,7 @@
+# v4.4.11
+- [fixed] Fixed a bug where settings updates weren't applied before fetches. (#4740)
+- [changed] Updated public API documentation for 4.4.10 change from FirebaseInstanceID to
+  FirebaseInstallations. (#5561)
 # v4.4.10
 - [changed] Internal code changes - migrate to using the FIS SDK. (#5096)
 - [changed] Include both CFBundleString and CFBundleShortVersionString in the outgoing fetch requests.

FirebaseRemoteConfig/Sources/FIRRemoteConfig.m

@@ -214,8 +214,10 @@ - (void)ensureInitializedWithCompletionHandler:
 #pragma mark - fetch
 
 - (void)fetchWithCompletionHandler:(FIRRemoteConfigFetchCompletion)completionHandler {
-  [self fetchWithExpirationDuration:_settings.minimumFetchInterval
-                  completionHandler:completionHandler];
+  dispatch_async(_queue, ^{
+    [self fetchWithExpirationDuration:self->_settings.minimumFetchInterval
+                    completionHandler:completionHandler];
+  });
 }
 
 - (void)fetchWithExpirationDuration:(NSTimeInterval)expirationDuration